Method of treating drupaceous fruit



United States Patent 3,356,511 METHOD OF TREATING DRUPACEOUS FRUIT DLoyd Hunter, 33- S. 2nd Ave., Yakima, Wash. 98902, and James R. Oyler,RD. 1, Biglerville, Pa. 17307 No Drawing. Filed Dec. 30, 1963, Ser. No.334,597 9 Claims. (Cl. 99193) ABSTRACT OF THE DISCLOSURE The method ofpitting drupaceous fruit comprising quick freezing the outer layer onlyof the fruit, then pitting the fruit, and then immediately freezing suchfruit solid throughout.

This invention relates to a method of handling cherries and otherdrupaceous fruits, and particularly to a method of pitting such fruits.

It has been proposed to cool cherries prior to pitting them for thepurpose of lessening the loss of juice during the pitting process. Ithas also been proposed to freeze cherries prior to pitting them for asimilar reason. The disadvantages of these methods are that asubstantial quantity of juice is still lost if the cherry is merelycooled, and while there is little loss of juice if the cherry is frozensolid, there is a substantial loss of flesh during the pittingoperation.

It is a main object of the present invention to provide a method ofpitting cherries and other drupaceous fruit that overcomes the abovedisadvantages. We have discovered that this can be done by subjectingcherries to a quick freezing step to cool only the outer layer of thecherry flesh below 32 Fahrenheit and leave the inner or center portionsabove 32 Fahrenheit, effecting the pitting operation while the cherriesare in such condition, and then freezing the cherries solid.

Various other objects will be apparent from the following description.

In preparing the cherries for the pitting operation, we have found thatthe ideal surface temperature of a cherry for pitting is around 29Fahrenheit and in any event within the range of 26-3 1 Fahrenheit.

The surface temperature can be obtained without freezing the interiorflesh of the cherry by subjecting the cherry, which is around 38Fahrenheit, to a quick cooling step, carried out at a temperature offrom 1015 Fahrenheit for a period of time of seven to twelve minutes.

The above surface cooling step can be effected by depositing thecherries on a mesh belt and moving the cherries over a cold blast ofair. We prefer to deposit the cherries on an upper belt, which travelsinto a cold air tunnel or chamber, and which, at the other end thereof,deposits the cherries on a lower belt, which conveys the cherries backout through the tunnel or chamber. The cherries are subject to the coldair blast while on both belts.

The pitting step can be carried out with a standard pitter, such as aDunkley pitter produced by Dunkley Co., of Kalamazoo, Michigan.

Immediately after the pitting step, the cherries are frozen solid. Thiscan be done on a mesh belt that carries the cherries over a cold airblast. At the beginning of the belt, the air temperature is arounddegrees Fahrenheit, and the air temperature drops until at the end, theair temperature is around 25 Fahrenheit. The cherries stay on this beltfor about twenty minutes.

With our method there is an optimum minimum loss of juice and flesh,i.e., practically no juice or flesh is lost. Also, our preliminary quickcooling step, followed by pitting, makes it easier to effect a finalfreezing of the cherries. In carrying out the preliminary quick coolingstep,

3,356,5 1 1 Patented Dec. 5, 1967 the cherries are handled so that theydo not freeze in clusters. If the latter occurred, it would makeseparation necessary in order to carry out the pitting operation.

In carrying out our preliminary quick cooling step, we have found thatoptimum results are obtained if the outer layer of the cherry is frozensolid to a thickness not less than one-twentieth of the radius of thecherry and not exceeding one-eighth of such radius. If the layer isthinner than above specified, excessive juice is lost, while if thelayer is thicker, excessive flesh is lost.

While the invention has been described in connection I with handlingcherries, and while the invention has particular application tocherries, the method of our invention can be applied to other drupaceousfruits with some benefit.

- Having described the invention in what is considered to be thepreferred embodiment thereof, it is desired that it be understood thatthe invention is not to be limited other than by the provisions of thefollowing claims.

We claim:

1. The method of pitting and handling drupaceous fruit to effect anoptimum minimum loss of juice and flesh, said method comprising,

quick cooling the fruit in a manner such as to freeze only the outerlayer of such fruit while leaving inner flesh portions unfrozen,

pitting the fruit While in such condition, and then immediately freezingsuch fruit solid throughout.

2. The method of pitting and handling drupaceous fruit to effect anoptimum minimum loss of juice and flesh, said method comprising,

quick cooling the fruit in a manner such as to freeze only the outerlayer of such fruit at a temperature of approximately 30 Fahrenheit,while leaving inner flesh portions unfrozen,

pitting the fruit while in such condition, and then immediately freezingsuch fruit solid throughout.

3. The method of pitting and handling drupaceous fruit to effect anoptimum minimum loss of juice and flesh, said method comprising quickcooling'the fruit in a manner such as to freeze only the outer layer ofsuch fruit at a temperature of approximately 30 Fahrenheit by a freezingstep carried out at a temperature of from 10 to 15 Fahrenheit for a timeof from 7 to 12 minutes while leaving inner flesh portions unfrozen,

pitting the fruit while in such condition, and then immediately freezingsuch fruit solid throughout.

4. The method of pitting and handling drupaceous fruit to effect anoptimum minimum loss of juice and flesh, said method comprising quickcooling the fruit in a manner such as to freeze only the outer layer ofsuch fruit at a temperature of between 24 and 30 Fahrenheit, whileleaving inner flesh portions unfrozen,

pitting the fruit while in such condition, and then immediately freezingsuch fruit solid throughout.

5. The method of pitting and handling drupaceous fruit to effect aminimum loss of juice and flesh, said method comprising quick coolingthe fruit in a manner such as to freeze only the outer layer of suchfruit to a thickness not less than one-twentieth of the radius of thefruit while leaving the inner flesh portions unfrozen,

pitting the fruit while in such condition, and then immediately freezingsuch fruit solid throughout.

6. The method of pitting and handling drupaceous fruit to effect anoptimum minimum loss of juice and flesh, said method comprising quickcooling the fruit in a manner such as to freeze only the outer layer ofsuch fruit to a thickness not r 3 4 greater than one-eighth of theradius of such fruit thickness not less than one-twentieth of the radiusof while leaving inner flesh portions unfrozen, the fruit and to athickness not greater than onepitting the fruit while in such condition,and then eighth of the radius of such fruit while leaving innerimmediately freezing such fruit solid throughout. flesh portionsunfrozen, 7. The method of pitting and handling drupaceous fruit 5pitting the fruit While in such condition, and then to effect an optimumminimum loss of juice and flesh, immediately freezing such fruit solidthroughout. said method comprising 9. The method of pitting and handlingdrupaceous fruit quick cooling the fruit in a manner such as to freezeto effect an optimum minimum loss of juice and flesh, said only theouter layer of such fruit to a thickness not method comprising less thanone-twentieth and not greater than one- 10 quick cooling the fruit in amanner such as to freeze eighth of the radius of such fruit whileleaving inner only the outer layer of such fruit while leaving innerflesh portions unfrozen, flesh portions unfrozen, and pitting the fruitwhile in such condition, and then p tting the fruit while in suchcondition. immediately freezing such fruit solid throughout. 8. Themethod of pitting and handling drupaceous fruit 15 References Clted toeflect an optimum minimum loss of juice and flesh, UNITED STATES PATENTSmath 2,103,925 1/1967 Zarotschenzeff 99-193 quick cooling the fruit in amanner such as to freeze only the outer layer of such fruit at atemperature HYMAN LORD, Primary Examiner. of approximately 26 Fahrenheitby a freezing step 20 carried out at a temperature of from 10 to 15LOUIS MONACELL Exammer' Fahrenheit for a time of from 7 to 12 minutes,to a M. VOET, Assistant Examiner.

1. THE METHOD OF PITTING AND HANDLING DRUPACEOUS FRUIT TO EFFECT ANOPTIMUM MINIMUM LOSS OF JUICE AND FLESH, SAID METHOD COMPRISING, QUICKCOOLING THE FRUIT IN A MANNER SUCH AS TO FREEZE ONLY THE OUTER LAYER OFSUCH FRUIT WHILE LEAVING INNER FLESH PORTIONS UNFROZEN, PITTING THEFRUIT WHILE IN SUCH CONDITION, AND THEN IMMEDIATELY FREEZING SUCH FRUITSOLID THROUGHOUT.